One of the world's prettiest campgrounds, the boat-in campground at Lake Tahoe's Emerald Bay, will open May 23 in time for Memorial Day weekend.

Across Northern California, it's well known that the big recreation lakes are low across the board for May. But a half dozen, including Ice House Reservoir in the Sierra Nevada and Lake Siskiyou in the north state, are right to the brim - and many more are in great shape.

In Yosemite Valley, waterfalls are at peak flow. A reservation for lodging or a drive-in campground is a must. In the high country, the wilderness is still snow-covered.

The recreation forecast for Memorial Day weekend is highlighted by new openings of facilities at Tahoe, lakes at their highest levels of the year (though many are far below typical levels for this time of year), and a good weather forecast.

Ah, the weather. It's been crazy.

Last Saturday night, it snowed four inches on the ridges surrounding Lake Tahoe, and on Mount Shasta above 8,500 feet. That was followed by record heat (but you know that, right?), including 91 Wednesday in Yosemite Valley. Next week, the forecast calls for rain (and snow above 9,000 feet) Wednesday or Thursday, then clear and warm for Memorial Day weekend.

Here's the outlook:

Lake Tahoe

Emerald Bay Boat-in Camp: Nestled in the pines on the shore of gorgeous Emerald Bay, these campsites are perfect with a kayak, with day hikes, paddles and adventures galore. Opens May 23, first-come, first-served, then by reservation starting June 13 (through Labor Day), with reservations available now at www.ReserveAmerica.com or (800) 444-7275.

D.L. Bliss: With no snow on the ground, D.L. Bliss, perched adjacent to Emerald Bay, also opened its campground, first-come, first-served. It goes on the reservation system June 11. Info: Lake Tahoe State Park Office, (530) 525-7232.

Campgrounds: Forest Service Campgrounds Kaspian, Meeks Bay, Fallen Leaf, Nevada Beach and Zephyr Cove will be open Friday; Luther Pass will open Sunday; Blackwood Canyon and Watson Lake will open June 1.

Trailheads: Eagle Falls, Glen Alpine, Bayview, Big Meadows and McKinney Rubicon will be open Friday; Echo will open May 23; Meeks and Tallac for Desolation closed by snow, no opening date set. Info: (530) 543-2600, www.fs.usda.gov/ltbmu (note: opening dates for facilities not posted).

Yosemite

Waterfalls: With temps in the low 90s Wednesday in Yosemite Valley, snowmelt is flooding the high country, down the creeks, and in turn, Yosemite, Vernal, Nevada and Bridalveil Falls are at peak flows for the year.

Roads: All park roads open, including Tioga Pass.

Lodging: In Yosemite Valley, Yosemite Lodge, Curry Village, Housekeeping Camp and the Ahwahnee are open. Outside of Yosemite Valley, the Wawona Hotel and Tenaya Lodge are open. On Tioga Road, Tuolumne Meadows Lodge and White Wolf Lodge are still closed by snow.

Campgrounds: Do not go to Yosemite to camp without a reservation; many camps will be closed until June.

Wilderness: The north and south rims of Yosemite Valley are about 80 percent snow covered, but clearing fast, with wet, mushy conditions, At Tuolumne Meadows, snow coverage on trails is 90 to 100 percent. Across the range, ice-out at lakes is now occurring at lakes from 6,500- to 8,000-foot elevations. With more hot weather, wilderness access will open up in early June.

Lassen Volcanic National Park

Roads: The park's main road, Lassen Park Highway/89, is projected to open before Memorial Day weekend. For this weekend, last Saturday's storm, with 8 inches of fresh snow, temporarily closed the road just inside the park entrances.

Campgrounds: All campgrounds now closed except for Southwest Walk-in, with Crags and Manzanita Lake expected to open May 23 for Memorial Day weekend. In the outskirts of the park, Butte Lake and Warner Valley are projected to open June 6.